I'd like to share my carparts.com experience with everyone. I purchased the rear (@cat) o2 sensor from them and they sent me the sensor for the rear manifold. So I returned it and they sent me the correct sensor. But they rejected the returned sensor saying it had been installed and could not be returned. Problem is it's in the exact condition they sold it to me (new). Now they keep lying to me saying they would not ship it back until it was looked into (I got it Monday), send me prepaid return info again (still waiting), etc. Every time I have talked to them during this ordeal what I was told never happened. I took advantage of the 33% off for this purchase but I may need 50% off or more to use them again........